Pyrotechnic hand flares



March 30, 1965 L. D. ABERG 3,175,493

PYROTEGHNIC HAND FLARES Filed July 9, 1963 INVEN TOR.

LARS DOUGLAS ABERG AYTORNEVS United States Patent 3,175,493 PYRQTECHNIC HAND FLARES Lars Douglas Aberg, Goteborg, Sweden, assignor to Alrtiebolaget Gotex, Goteborg, Sweden, a corporation of Sweden Filed July 9, 1963, Ser. No. 293,698 Claims priority, application Sweden, July 26, N62, $,249/ 62 1 Claim. (Cl. 102-318) The present invention relates to pyrotechnic hand flares used for signalling at sea. Such flares contain a pyrotechnic mass developing, when burning, light or smoke of varying colors. Said mass is enclosed in a pyrotechnic case having at one end an ignition device and at the other end a handle. For certain reasons, a metal tube' is preferred as the protecting case. Since the burning pyrotechnic mass will develop a very high temperature it has up to now been difficult to fit a strong and steady handle in direct connection to the end of the pyrotechnic mass Without the handle getting too hot from the heat produced. Hitherto, the handle has been made from wood or millboard having, however, the drawbacks arising from variations of the atmospheric humidity which has a deleterious effect on the securing of the handle if a moderate building length thereof is to be obtained. lhe present invention has for its object to eliminate said drawbacks.

The present invention has for its object to provide a pyrotechnic hand flare having means for reducing the heat transmission from one part of the case receiving the pyrotechnic mass to another part of the case serving as handle for the flare.

Another object of the invention is to provide a hand flare which will be simple in construction, cheap in manufacture and which, when burning, can be handled without difliculties in spite of the high temperature developed by the burning of the mass.

Other objects of the invention will be made clear by the following description.

The case of the hand flare enclosing the pyrotechnic mass is preferably of metal, and according to the invention the case is extended past the pyrotechnic mass by a case portion constituting a handle or a part thereof and merging into the case portion containing the pyrotechnic mass by connecting parts having a reduced heat conducting area in relation to said case. By preference, said connecting parts comprise bridges between the case portion containing the pyrotechnic mass and the handle portion of the case, said bridges being separated from each other by slots, bores or apertures. Said slots or the like in the peripheral direction of the case have substantially greater extension than the bridges.

By said connecting parts and slots the conduction of heat to the handle portion of the case will be reduced in a high degree permitting a person to hold the handle of the burning flare in his or her bare hand without any trouble from the heat generated by the combustion of the pyrotechnic mass.

The invention is illustrated by the accompanying drawing showing as an example an embodiment of the invention. FIG. 1 shows an axial section of the flare. FIG. 2 is a cross-section on the line IIII of FIG. 1.

The tubular case of the flare is preferably made from metal and comprises a portion 1 containing the pyrotechnic mass 2 and a portion 1 designed to constitute, wholly or partially, the handle of the flare. The mass 2 is separated from the handle portion 1' by a moisture insulating bottom or wall 8 inserted and attached to the end of the case portion 1, which bottom or wall may be composed of several layers of materials suitable for the purpose. The end of the case portion 1 opposite to said bottom or wall has an ignition device indicated generally by A. This device may be of a known design and comprises a striker pin 3, which is spring-operated and releasable by hand, and a percussion cap or primer 4. The case portions l and 1 are made integrally from a cylindrical pipe or tube and merge into each other by two or more bridges 5 which are left after breaking through the wall of the tubular case by slots 6, bores or apertures or the like. According to the drawing, three bridges 5 are provided and these occupy only a small fraction of the circumference of the case whereas the remaining portion thereof is broken through by the slots. Only as an example it may be mentioned that the case 1, 1 may have an outer and an inner diameter of 31 and 30 mm. respectively. In this case three slots 6 are provided which are spaced an equal angular distance from each other, said slots having a width of about 2 and such a length that three bridges 5 are remaining having a Width (in peripheral direction) of about 5 mm. The cross-sectional area of the bridging portions thus provided between the two case portions 1 and It will substantially restrict the heat transmission from the burning pyrotechnic mass 2 through the case portion 1 to the case portion 1'. In tests made it has turned out that such a flare can without any difficulty be held by the naked hand in the immediate vicinity of the slots 6 when a pyrotechnic mass is burning at a temperature estimated to be about 25 00 Celsius.

As before mentioned, the handle 1 does not need in its entirety to consist of a portion of the metal case. In the end of the portion 1 opposite to the slots 6, for example, a ring or sleeve 7 of plastic may be secured, said ring or sleeve covering the free edge of the portion 1 and extending the handle in some measure.

What I claim is:

A pyrotechnic hand flare device comprising a tubular case having substantially the same inner and outer diameter throughout its entire length, a pyrotechnic mass contamed in a first tubular portion of said case, a second tubular portion of said case, extending beyond said pyrotechmc mass and constituting a hollow handle for the hand flare, substantially rigid bridges permanently connectingsaid first and second tubular portions of said case, said first and second tubular portions and said bridge portions being a single piece of tubing, said case having apertures therein between and separating said bridge portions, said bridge portions having substantially smaller extension in the peripherial direction of said case than said apertures.

References Cited by the Examiner UNITED STATES PATENTS 648,817 5/00 Warner 10237.8 1,029,051 6/12 Dutcher 102-3752 2,179,815 8/39 Eroe 10237.8 X

SAMUEL FEINBERG, Primary Examiner. 

